Immigrants can help reveal role of environment

Researchers at the University of Michigan hope to isolate environmental factors that contribute to cancer by comparing immigrant populations in this country with people in their places of origin.

For example, an unusual cancer pattern occurs in North Africa, where inflammatory breast cancer, a particularly deadly form, makes up about 10 percent of breast cancer cases. Yet in the United States it constitutes only about 1 percent of breast cancer cases. Is this anomaly because of genetic, lifestyle or environmental differences?

By comparing American immigrants to the people in their native lands, the researchers from the U. of M. School of Public Health think they might find out.

This new two-year master's program, Cancer Epidemiology Education in Special Populations, is headed by Dr. Amr Soliman, assistant professor of epidemiology.

"People in developing countries are exposed to intense environmental exposures [in the form of industrial and agricultural waste]," Soliman said. "And studying people and doing research on populations with intense environmental exposures would let us understand why people get cancer here in the United States. The environmental exposures would be the same in the United States and in other countries, but the levels of exposures would be higher in developing countries [due to lax or unenforced regulations], and this would help us understand what environmental exposures would lead to certain cancers."

Lifestyle differences must also be considered, although they don't always explain elevated cancer rates.

"We've studied young-onset colon cancer in Egypt, where we see 35 percent of the cases under age 40," Soliman said. "This is very unusual. Here in the United States and Western countries, young-onset colon cancer constitutes between 2 to 6 percent of all colorectal cancer cases. And it's interesting, because the lifestyle in Egypt is the lifestyle of a high fiber, low-fat, low-meat, low-calorie diet. ... So this is a good place to study the effect of environmental exposure."

"People do not change their genes ... so these types of migration studies would let us understand also the causes of cancers," explained Soliman, who received a $1.2 million grant from the National Cancer Institute for the program.

Kenneth Warner, dean of the university's School of Public Health, said, "I think it's a very exciting opportunity. It combines our interest in specific diseases, in this case cancer, with our core strength in epidemiology. And in addition to the research potential in it, it involves the exchange of students and scholars. ... It's very interesting, and in terms of developing practical knowledge about how to deal with cancers, it can be a very useful study."